Dental Milling System

ABSTRACT

Systems and methods are provided for machining dental prostheses including, over a network, receiving data concerning a dental prosthesis, selecting a material from which to machine the dental prosthesis, and determining machining instructions for machining the dental prosthesis based on a nominal enlargement factor corresponding to the selected material. The method can also include storing the machining instructions, receiving a request from a milling machine for a dental prosthesis to be milled by the milling machine, and associating the dental prosthesis with the milling machine. The method can also include selecting a material blank comprised of the selected material, determining a material blank enlargement factor of the selected material blank, modifying the machining instructions according to a difference between the nominal enlargement factor and the material blank enlargement factor, and machining the dental prosthesis according to the modified machining instructions.

CROSS-REFERENCE TO CORRESPONDING APPLICATIONS

This application is a continuation patent application of U.S. patentapplication Ser. No. 14/674,629 filed Mar. 31, 2015, which isincorporated by reference herein in its entirety.

FIELD

The present disclosure relates to systems and methods of manufacturingdental prostheses.

BACKGROUND

Dental prostheses are typically manufactured at specialized dentallaboratories that employ computer-aided design (CAD) and computer-aidedmanufacturing (CAM) milling systems to produce dental prosthesesaccording to patient-specific specifications provided by dentists. In atypical work flow, information about the oral situation of a patient isreceived from a dentist, the dental laboratory designs the dentalprosthesis, and the prosthesis is assigned to a block of material, ormaterial blank, having size, shape, color, and material-type propertiessuitable for creating the prosthesis. The material blank is generally apre-sintered ceramic, and is associated with unique predeterminedshrinkage information corresponding to a factor by which the materialblank will shrink when fully sintered. Many conventional dental millingsystems then determine numerical code for machining the dentalprosthesis that accounts for the unique shrinkage information associatedwith the assigned material blank, thereby tying the production of thedental prosthesis to the assigned material blank. Thus, a given dentalprosthesis cannot be manufactured until the specified material blank isplaced in a milling machine, which can slow production of dentalprostheses, and reduce system resiliency to equipment failure.Accordingly, improvements to dental milling systems are desirable.

SUMMARY

Certain embodiments of the disclosure concern systems and methods formachining dental prostheses including, over a network, receiving dataconcerning a dental prosthesis, selecting a material from which tomachine the dental prosthesis, and determining machining instructionsfor machining the dental prosthesis based on a nominal enlargementfactor corresponding to the selected material. The method can furthercomprise storing the machining instructions, receiving a request from amilling machine for a dental prosthesis to be milled by the millingmachine, and associating the dental prosthesis with the milling machine.The method can further comprise selecting a material blank comprised ofthe selected material, determining a material blank actual enlargementfactor of the selected material blank, modifying the machininginstructions according to a difference between the nominal enlargementfactor and the material blank actual enlargement factor, and machiningthe dental prosthesis according to the modified machining instructions.

In another representative embodiment, a system comprises a dentalprosthesis database to, over a network, receive and store dataconcerning a dental prosthesis, and a machining instructions tool todetermine machining instructions for machining the dental prosthesisbased at least in part on the data concerning the dental prosthesis anda nominal enlargement factor. The system further includes a dentalprosthesis selection module to associate the machining instructions witha milling machine based on a request from the milling machine for adental prosthesis to be milled by the milling machine, and a controllerto select a material blank, determine a material blank actualenlargement factor of the selected material blank, and modify themachining instructions according to a difference between the nominalenlargement factor and the material blank actual enlargement factor. Themilling machine can be communication with the controller, and can beconfigured to receive the modified machining instructions and to machinethe dental prosthesis according to the modified machining instructions.

Another representative embodiment includes one or more non-transitorycomputer-readable media storing computer executable instructions forcausing a computer to perform a method, the method comprising over anetwork, receiving data concerning a dental prosthesis, selecting amaterial from which to machine the dental prosthesis, and determiningmachining instructions for machining the dental prosthesis based on anominal enlargement factor corresponding to the selected material. Themethod can further comprise storing the machining instructions,receiving a request from a milling machine for a dental prosthesis to bemilled by the milling machine, associating the dental prosthesis withthe milling machine, selecting a material blank comprised of theselected material, and determining a material blank actual enlargementfactor of the selected material blank. The method can further comprisemodifying the machining instructions according to a difference betweenthe nominal enlargement factor and the material blank actual enlargementfactor, and machining the dental prosthesis according to the modifiedmachining instructions.

The foregoing and other objects, features, and advantages of thedisclosed embodiments will become more apparent from the followingdetailed description, which proceeds with reference to the accompanyingfigures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a representative embodiment of adental milling system.

FIG. 2 is a plan view of a physical implementation of a mill group ofthe dental milling system of FIG. 1.

FIG. 3 illustrates a representative embodiment of a disk-shaped materialblank.

FIG. 4 is a plan view of the material blank of FIG. 3 illustrating aplurality of dental prostheses milled into the material blank.

FIG. 5 illustrates a representative embodiment of a rectangularly-shapedmaterial blank.

FIG. 6 is a cross-sectional view of the material blank of FIG. 5illustrating representative height and width dimensions prior to andafter final sintering.

FIG. 7 is a schematic illustration of a representative embodiment of adental prosthesis management system.

FIG. 8 is a schematic illustration of a representative embodiment of amill group control module.

FIG. 9 is a block diagram illustrating exemplary dental prosthesisinformation.

FIG. 10 is a block diagram illustrating exemplary material blankinformation.

FIG. 11 is a schematic block diagram illustrating a representativemethod of milling a dental prosthesis.

FIG. 12 is a schematic illustration of a representative computingenvironment in which described embodiments, techniques, and technologiescan be implemented.

DETAILED DESCRIPTION General Considerations

For purposes of this description, certain aspects, advantages, and novelfeatures of the embodiments of this disclosure are described herein. Thedisclosed methods, apparatus, and systems should not be construed asbeing limiting in any way. Instead, the present disclosure is directedtoward all novel and nonobvious features and aspects of the variousdisclosed embodiments, alone and in various combinations andsub-combinations with one another. The methods, apparatus, and systemsare not limited to any specific aspect or feature or combinationthereof, nor do the disclosed embodiments require that any one or morespecific advantages be present or problems be solved.

Although the operations of some of the disclosed embodiments aredescribed in a particular, sequential order for convenient presentation,it should be understood that this manner of description encompassesrearrangement, unless a particular ordering is required by specificlanguage set forth below. For example, operations described sequentiallymay in some cases be rearranged or performed concurrently. Moreover, forthe sake of simplicity, the attached figures may not show the variousways in which the disclosed methods can be used in conjunction withother methods. Additionally, the description sometimes uses terms like“provide” or “achieve” to describe the disclosed methods. These termsare high-level abstractions of the actual operations that are performed.The actual operations that correspond to these terms may vary dependingon the particular implementation and are readily discernible by one ofordinary skill in the art.

As used in this application and in the claims, the singular forms “a,”“an,” and “the” include the plural forms unless the context clearlydictates otherwise. Additionally, the term “includes” means “comprises.”Further, the terms “coupled” and “associated” generally meanelectrically, electromagnetically, and/or physically (e.g., mechanicallyor chemically) coupled or linked and does not exclude the presence ofintermediate elements between the coupled or associated items absentspecific contrary language.

In some examples, values, procedures, or apparatus may be referred to as“lowest,” “best,” “minimum,” or the like. It will be appreciated thatsuch descriptions are intended to indicate that a selection among manyalternatives can be made, and such selections need not be better,smaller, or otherwise preferable to other selections.

In the following description, certain terms may be used such as “up,”“down,” “upper,” “lower,” “horizontal,” “vertical,” “left,” “right,” andthe like. These terms are used, where applicable, to provide someclarity of description when dealing with relative relationships. But,these terms are not intended to imply absolute relationships, positions,and/or orientations. For example, with respect to an object, an “upper”surface can become a “lower” surface simply by turning the object over.Nevertheless, it is still the same object.

Example 1—Representative Dental Milling System

In a conventional dental milling system workflow, information used todesign and manufacture a dental prosthesis for a patient is receivedfrom a dentist or dental office. In some representative examples, adentist or dental office will provide information concerning the oralsituation of a patient, such as a physical impression or an electronicfile containing a digital scan of the patient's oral situation.Additionally, the dentist or dental office may also provide instructionsfor the material or materials to be used to manufacture the prosthesis,the type and construction of the prosthesis, the shade or otheraesthetic features for the prosthesis, and the like. As used herein, theterm “dental prosthesis” refers to any dental restorative including,without limitation, crowns, bridges, dentures, partial dentures,implants, onlays, inlays, or veneers, to name a few. Using the foregoinginformation, a dental laboratory will design a dental restoration,typically using a design software package such as FastDesign™ dentaldesign software available from IOS Technologies, Inc. of San Diego,Calif. CAD/CAM machining instructions (also referred to as “numericalcode” or “NC code”) are determined based upon the type of restoration,the digital design of the dental prosthesis, and the selected material,and a material blank or ingot comprised of the specified material isplaced into a milling machine, which mills (i.e., “machines”) the dentalprosthesis from the material blank according to the machininginstructions. The milled prosthesis is then removed from the millingmachine for further processing consistent with the type of material orprosthesis (e.g., sintering, polishing, etc.), and the final dentalprosthesis is packaged for delivery to the dentist.

Typically, the material blanks comprise a ceramic material, and are in apre-sintered or partially sintered state such that the material blankscan be easily milled by the milling machine. After milling, theresulting pre-sintered or partially sintered dental prostheses can becolored with various pigments to match the shade of the patient'snatural dentition, and then fully sintered to harden the dentalprostheses. In other embodiments, the material blanks are formed of amaterial that includes coloring agents to match or approximate the shadeof the patient's natural dentition, or any other desired shade. Thefinal sintering process can cause the pre-sintered or partially sintereddental prostheses to experience a dimensional reduction, or shrink. Theamount of shrinkage that a ceramic material will undergo during finalsintering is often unique to each material blank, and may be expressedas a ratio D₀/D_(F), where D₀ is an initial dimension of the materialblank prior to final sintering and D_(F) is a final dimension of thematerial blank after final sintering (see, e.g., FIG. 6). The ratioD₀/D_(F) can define an enlargement factor of the material blank, whichmay be predetermined based upon batch material properties and diagnosticmeasurements of the individual material blank. In some embodiments, anenlargement factor may be derived theoretically based upon the materialused in the blank and its properties. In other embodiments, anenlargement factor is determined via measurements (e.g., physicaldimensions, displacement, weight) of the actual material blank. In someexamples, the enlargement factor of a material blank may range in valuefrom about 1.1 to about 1.3, depending upon the type of ceramicmaterial.

In some exemplary embodiments, an enlargement factor is determined basedupon volumetric measurements. Because the target densities of manysintered ceramic materials (e.g., zirconia) are known, the amount ofshrinkage that occurs during sintering may be predicted very accurately.For example, the size of a milling blank may be measured using acoordinate measuring machine (CMM) or other device to obtain a volume ofthe blank, and its weight may be measured. From these measurements, thedensity of the pre-sintered or partially sintered milling blank may beascertained. The enlargement factor for the milling blank is thencalculated as the cube root of the ratio of the target density to the(measured) pre-sintered or partially sintered density:

${EF} = \sqrt[3]{\frac{\rho \left( {{fully}\mspace{14mu} {densified}} \right)}{\rho \left( {{pre}\text{-}{sintered}} \right)}}$

Depending upon the material used to manufacture the material blank, themanufacturing method, or other factors, the material blank may be eitherisotropic or it may be anisotropic, e.g., having different shrinkagecharacteristics along different axes of the blank. For example, amaterial blank that is manufactured using an isostatic pressing methodmay have shrinkage characteristics that are different from a blank thatis manufactured using biaxial or uni-axial pressing. In some cases,therefore, a material blank may possess an enlargement factor in its XYorientation that is different from the enlargement factor in the Zdirection (directions being expressed using a conventional Cartesiancoordinate system that is recognized by those skilled in the art). Thedental milling systems and methods described herein are adapted for andare suitable for use with either isotropic or anisotropic dentalmaterial blanks.

In order for a dental prosthesis to achieve the desired size and shapeafter final sintering, the machining instructions for machining thedental prosthesis must account for the unique enlargement factor of thematerial blank from which the dental prosthesis will be milled. This canbe done by, for example, increasing the dimensions of the dentalprosthesis when initially milled from the partially sintered materialblank by a factor equal to the enlargement factor of the material blank.In other words, oversizing the dental prosthesis according to theenlargement factor of the material blank from which the dentalprosthesis is machined can help to ensure that the dental prosthesisshrinks to the desired size after final sintering.

FIG. 1 is a schematic illustration of a representative embodiment of adental milling system 100 including a dental prosthesis managementsystem 102 and a plurality of mill groups 104A-104C. The dentalprosthesis management system 102 can include a dental prosthesisselection module 120 and a machining instructions tool 130, and can bein communication with each of the mill groups 104A-104C such that it cancoordinate the operation of the mill groups to produce dentalprostheses, as further described below.

Each of the mill groups 104A-104C can include one or more mills, amanipulator, a material blank cassette (also referred to as a “tray” or“rack”), and a mill group control module (also referred to as a“controller”). For example, FIG. 2 illustrates an exemplary mill group104A including four milling machines 106A-106D (also referred to as“mills”), a material blank cassette 108, a manipulator 110, and a millgroup control module 112 that coordinates the operation of the mills106A-106D with the cassette 108 and the manipulator 110.

Referring to FIGS. 3-6, the cassette 108 (FIGS. 1 and 2) can include aplurality of material blanks such as representative material blank 200illustrated in FIGS. 3 and 4, and/or representative material blank 300illustrated in FIGS. 5 and 6. The material blank 200 of FIG. 3 can havea disk-shaped body 202, and can have a diameter and thickness suitablefor machining a plurality of dental prostheses 206 from a singlematerial blank, as shown in FIG. 4. The material blank 300 of FIG. 5 canhave an elongated body 302 and a rectangular cross section, as shown inFIG. 6. Although representative disk-shaped and elongated-shapedmaterial blank bodies are illustrated in the figures, in otherembodiments, the material blank has other geometric or non-geometricshapes or forms, provided that the size and shape of the blank issufficient to produce the desired dental prosthesis. In someembodiments, the material blank 300 can be suitable for milling a singledental prosthesis (e.g., a crown), or a small number of dentalprostheses, depending upon the size of the material blank and the dentalprosthesis or prostheses to be milled.

Referring to the material blank 300 for purposes of illustration, FIG. 6schematically illustrates the relative size of a cross-section of thematerial blank 300 when partially sintered (indicated in solid lines)and after final sintering (indicated in phantom). The initial and finalheights of the material blank 300 are illustrated by dimensions H₀ andH_(F), and the initial and final widths are illustrated by dimensions W₀and W_(F). As described above the, ratios H₀/H_(F) and W₀/W_(F) candetermine the material blank enlargement factor of the material blank300, which must be accounted for when determining the machininginstructions for machining a dental prosthesis to help ensure that thedental prosthesis achieves the desired size after machining and finalsintering.

Referring again to FIGS. 3 and 5, the material blanks 200, 300 caninclude respective barcodes 204, 304, which can include informationregarding the material blanks 200, 300, such as the enlargement factorsof the respective material blanks 200, 300. In some embodiments, thematerial blanks 200, 300 can comprise any biocompatible ceramic,including silica-, alumina-, leucite-, and/or zirconia-based ceramics,or any combination thereof. In one representative embodiment, thematerial blanks 200, 300 can be made from Prismatik Clinical Zirconia™available from Glidewell Laboratories. The material blanks 200, 300 canalso be of any suitable shape, size, and/or color shade, and thecassette 108 can include a plurality of examples of material blankshaving any such shape, size, and/or color shade combination, as desired.

In the exemplary embodiment of FIGS. 1 and 2, the control module 112, inresponse to instructions from the dental prosthesis management system102, can cause the manipulator 110 to pick a material blank from thecassette 108 and place it into one of the mills 106A-106D for milling bythe mill. In some embodiments, the manipulator 110 can be a robotic arm,as shown in FIG. 2. In some embodiments, the manipulator 110 and/or themill into which the material blank is placed can include a barcodereader or other device to scan the barcode associated with the materialblank, and can transmit information concerning the material blank to thedental prosthesis management system 102. The milling machine can thenmachine a dental prosthesis, shown schematically at 116, according tomachining instructions provided by the machining instructions tool 130.After milling, the manipulator 110 can remove the milled dentalprosthesis 116 from the mill and place it, for example, on a conveyor114, which can convey the dental prosthesis 116 away from the mill group104A for further processing. The manipulator 110 can load materialblanks into the various mills 106A-106D and unload milled dentalprostheses from the mills 106A-106D as instructions are received fromthe dental prosthesis management system 102.

Although three mill groups 104A-104C are illustrated in FIG. 1, itshould be understood that the milling system 100 can include anysuitable number of mill groups. Further, the mill groups can include anysuitable number of mills, manipulators, cassettes, and/or controllers,as desired. It should also be understood that the mills such as mills106A-106D need not be grouped into mill groups, but may be arranged inany suitable arrangement, including a plurality of discrete mills, or asingle mill, and may be located locally or remotely (for example,chair-side in a dental office) with respect to the dental prosthesismanagement system 102, as desired. Additionally, the mills 106A-106D,the cassette 108, and the manipulator 110 of each of the mill groups104A-104C can include their own internal controller(s), memory, andprocessors to execute instructions received from the respective millgroup control modules, such as control module 112, and/or from thedental prosthesis management system 102.

Example 2—Representative Dental Prosthesis Management System

The dental prosthesis management system 102 can be any system capable ofperforming tasks related to the manufacture of dental prostheses, andcan be implemented on a computer system, such as a server. Referring toFIG. 7, the dental prosthesis management system 102 can include thedental prosthesis selection module 120, the machining instructions tool130, and a dental prosthesis database 150. The machining instructionstool 130, in turn, can include a nominal enlargement factor database 132and a machining instructions database 134. The databases 150, and 134can be internal to the dental prosthesis management system 102, locatedon an external device connected to the dental prosthesis managementsystem 102, or located remotely, such as in cloud-based storage.

In practice, the systems shown herein, such as the dental prosthesismanagement system 102 can vary in complexity, with differentfunctionality, components of differing complexity, and the like.Further, although a single instance is shown, a large number ofinstances, some sharing data, databases, configuration information, andthe like, can be supported. Also, the dental prosthesis managementsystem 102 can comprise a variety of other functionality not shown toaddress synchronization, security, load balancing, multi-tenancy,redundancy, and the like.

Although various components of the systems herein are shown as a singlecomponent, in practice, the boundaries between components can bechanged. For example, although the system is shown as executing on asingle server, in practice, functionality can be implemented across oneor more machines, virtual or physical.

The dental prosthesis management system 102, any of the other systemsdescribed herein, and subsets of such systems can be implemented inconjunction with any of the hardware components described herein, suchas the described computing systems (e.g., processing units, memory, andthe like). In any of the examples herein, the inputs, outputs,databases, documents, and the like can be stored in one or morecomputer-readable storage media or computer-readable storage devices.The technologies described herein can be generic to the specifics ofoperating systems or hardware and can be applied in any variety ofenvironments to take advantage of the described features.

As illustrated in FIG. 7, the nominal enlargement factor database 132can include nominal enlargement factors 136 corresponding to thedifferent material types from which material blanks in the variouscassettes, such as cassette 108, are comprised. The nominal enlargementfactors 136 can be, for example, average values of the enlargementfactors corresponding to the respective material types. For example, fora zirconia-based ceramic having an enlargement factor typically rangingfrom about 1.21 to about 1.24, the nominal enlargement factor 136 forthat zirconia-based ceramic can be about 1.225. The nominal enlargementfactor database 132 can store a plurality of nominal enlargement factors136 corresponding to a plurality of materials, and the nominalenlargement factors 136 can be periodically updated as necessary toreflect different materials or material properties as, for example, newmaterial blanks are received by the dental milling system 100.

As described in more detail below, a “nominal enlargement factor” 136 isa value that is used to generate an initial set of machininginstructions 138 for machining a given dental prosthesis 116 from amaterial blank. The initial set of machining instructions 138 that aregenerated using the nominal enlargement factor 136 are later adjusted(via a correction factor) to account for the difference between thenominal enlargement factor 136 and the actual enlargement factor for thematerial blank being used to generate the dental prosthesis 116. In someembodiments, the nominal enlargement factor 136 may be derivedempirically (e.g., as an average or mean value of a number of examples),or it may be a theoretical value derived from the properties of thematerial used in the material blank, or it may be selected based uponother criteria.

The dental prosthesis management system 102 can receive dentalprosthesis information 152 associated with a dental prosthesis 116 to bemilled by the dental milling system 100, which can be used to create oneor more entries in the dental prosthesis database 150. In someembodiments, the dental prosthesis database 150 can be implemented as aqueue or a first-in-first-out data structure, in which dental prostheses116 are selected for milling in the order in which their associateddental prosthesis information 152 was received by the dental millingsystem 100. Other implementations are possible, including a structure inwhich dental prosthesis information 152 concerning certain dentalprostheses 116 can be weighted or prioritized such that dentalprostheses 116 selected for machining are not necessarily selected inthe order in which they were received (to allow prioritization of rushorders, for example).

The dental prosthesis information 152 can be passed to the machininginstructions tool 130, which can select the material type from which thedental prosthesis is to be manufactured (based on, for example, amaterial specified by the dentist or determined according to the type,size, etc., of the dental prosthesis), and retrieve a nominalenlargement factor 136 for that material type from the nominalenlargement factor database 132. The machining instructions tool 130 canthen determine machining instructions 138 (for example, numerical code)for machining the dental prosthesis 116 according to the nominalenlargement factor 136, and store the machining instructions 138 in themachining instructions database 134.

For purposes of illustration, the following description proceeds withrespect to mill 106A of mill group 104A of FIGS. 1 and 2. However, itshould be understood that the following description is applicable to anyof the mills and/or mill groups described herein. When mill 106A isavailable for a new dental prosthesis milling job, the control module112 can transmit a dental prosthesis request 122, which can be receivedby the dental prosthesis management system 102. The dental prosthesisselection module 120 can then query the dental prosthesis database 150concerning dental prosthesis information 152 for a dental prosthesis tobe milled by the mill 106A. The dental prosthesis database 150 canidentify the dental prosthesis 116 as the next dental prosthesis to bemilled. The dental prosthesis selection module 120 can then send amachining instructions request 124 to the machining instructions tool130 requesting the machining instructions 138 associated with the dentalprosthesis 116. The machining instructions tool 130 can retrieve theappropriate machining instructions 138 from the machining instructionsdatabase 134, and provide the machining instructions 138 to the dentalprosthesis selection module 120 in a machining instructions response126. The dental prosthesis management system 102 can then transmit themachining instructions 138 to the mill group control module 112. In someembodiments, the machining instructions 138 can include informationindicative of the nominal enlargement factor 136 upon which themachining instructions 138 are based.

FIG. 8 schematically illustrates a representative embodiment of the millgroup control module 112. The control module 112 can include a machininginstructions modification tool 160, a machining instructions database162, a modified machining instructions database 164, a material blankinformation database 166, and a correction factor database 168.Additionally, although the mill group control module 112 is shown as aseparate entity from the mills 106A-106D, it should be understood thatany of the disclosed functionality can also be carried out by, forexample, one or more discrete controllers (and/or other associatedhardware or software features) associated with each individual millingmachine 106A-106D.

The control module 112 can receive the machining instructions 138associated with the dental prosthesis 116 and information of the nominalenlargement factor 136, which can be stored in the machininginstructions database 162. The control module 112 can then transmitcontrol signals for causing the manipulator 110 to select a materialblank from the cassette 108, obtain material blank information 170 (by,for example, scanning a barcode associated with the material blank), andplace the material blank in the mill 106A. In some embodiments, thematerial blank information 170 can include data concerningidentification of the material blank and the material blank actualenlargement factor, as further described below with respect to FIG. 10.In some embodiments, the material blank can also be selected based atleast in part on, for example, a size of the material blank, a shade ofthe material blank, and/or the type of prosthesis being manufactured(e.g., a posterior crown, an anterior crown, a posterior bridge, ananterior bridge, an inlay, an onlay, or the like), as desired.

The material blank information 170 can be returned to the control module112 and stored as one or more entries in the material blank informationdatabase 166. In some embodiments, certain of the material blankinformation, such as the material blank actual enlargement factor, canbe initially stored in the material blank information database 166 when,for example, the material blank is initially inventoried, andsubsequently retrieved from the material blank information database 166when the corresponding material blank is selected for milling a dentalprosthesis. In alternative embodiments, the material blank informationdatabase 166 can be associated with the dental prosthesis managementsystem 102, and the material blank information 170 can be transmitted tothe dental prosthesis management system 102 for storage.

In some embodiments, the material blank information 170 can include amaterial blank actual enlargement factor 172 specifying an enlargementfactor value specific to the particular material blank associated withthe material blank information 170. The machining instructionsmodification tool 160 can then determine a correction factor 174, whichcan be given by the expression below. The correction factor 174 canrepresent a difference between the nominal enlargement factor 136 usedto determine the machining instructions 138 and the material blankactual enlargement factor 172, and can be stored in the correctionfactor database 168.

Correction Factor=1−(Nominal EF−Material Blank Actual EF)

Using the correction factor 174, the machining instructions modificationtool 160 can determine modified machining instructions 176 (for example,by altering the tool path of a milling tool) based at least in part onthe machining instructions 138 and the correction factor 174. In thismanner, the modified machining instructions tool 160 can account for thedifference between the nominal enlargement factor 136 and the materialblank actual enlargement factor 172. The modified machining instructions176 can then be stored in the modified machining instructions database164, and/or transmitted to the mill 106A, which can mill the dentalprosthesis 116 from the material blank according to the modifiedmachining instructions 176. For example, in some embodiments, themodified machining instructions 176 are not stored in the modifiedmachining instructions database 164. Rather, the machining instructions138 are modified line by line by scaling each command by the correctionfactor 174 as each command is processed in order to generate themodified machining instructions 176.

As noted previously, in some embodiments a material blank may possess anenlargement factor in its XY orientation that is different from theenlargement factor in the Z direction. In these embodiments, thecorrection factor 174 will include components that account for thedifference by having different values depending upon the orientation ofthe machining instructions command. The modified machining instructionstool 160 applies the appropriate correction factor 174 component to eachcommand as the modified machining instructions 176 are generated.

For example, for a representative dental prosthesis to be milled from azirconia-based ceramic, machining instructions 138 can be determined bythe machining instructions tool 130 according to a nominal enlargementfactor of 1.225, as described above. When the machining instructions 138are provided to a mill group control module, such as control module 112,in response to a request for a dental prosthesis to be milled, thecontrol module 112 can obtain the material blank enlargement factor 172corresponding to the material blank from which the dental prosthesiswill be milled (e.g., by causing a barcode reader to scan the barcodeassociated with the material blank). The control module 112 can thendetermine the correction factor 174 based on the material blank actualenlargement factor 172. For example, if the selected material blank hasan associated material blank enlargement factor 172 of 1.230, then thecorrection factor 174 can be determined to be about 1.005. Using thecorrection factor 174, the machining instructions modification tool 160can then modify the machining instructions 138 based at least in part onthe correction factor 174, and store the modified machining instructions176 in the modified machining instructions database 164 and/or providethe modified machining instructions 176 to the mill 106A.

Those skilled in the art will recognize that a relatively largercorrection factor 174 can potentially lead to a larger degree of errorin the modified machining instructions 176 relative to a situation inwhich the machining instructions are originally created based upon thematerial blank actual enlargement factor 172. As a result, it isadvantageous to have a correction factor 174 having a value as close aspossible to 1.000. It follows that it is advantageous to have a nominalenlargement factor 136 that is as close as possible to the materialblank actual enlargement factor 172. This error reduction alsodemonstrates at least one reason why it is advantageous to provide anominal enlargement factor 136 in the process of generating the initialmachining instructions 138, rather than generating the instructionsusing a 1:1 scale with the resulting relatively larger correction factor174.

The manufacturing systems and methods described herein provide theability to generate an initial set of machining instructions 138 thatare based upon the dental prosthesis information 152 prior to the timethat the machining instructions 138 are associated with a specificmaterial blank. This allows the dental milling system 100 to mill dentalprostheses with any available milling machine using any material blankavailable to that machine because the machining instructions formachining the dental prostheses can be determined independent of thespecific material blanks from which the dental prostheses will bemilled. Thus, unlike conventional dental milling systems, whichdetermine the machining instructions for a given dental prosthesisaccording to an enlargement factor for a particular material blank, thiscan provide the ability to assign dental prosthesis milling jobs tomills and/or mill groups on an as-requested basis without regard towhether a particular material blank is available for use by that mill ormill group (i.e., located in a cassette associated with that mill ormill group). In other words, by determining the machining instructions138 according to a nominal enlargement factor 136 and modifying themachining instructions according to a material blank enlargement factor172 associated with a particular material blank only after that materialblank is selected for milling the dental prosthesis, dental prosthesismilling jobs can be distributed to any available milling machine in thesystem at any time. This can speed the production of dental prosthesesbecause any dental prosthesis can be milled by any mill using anymaterial blank. This can also provide flexibility and resiliency toequipment failures because, for example, if one or more milling machines(or manipulators, controllers, etc.) fail prior to or during milling ofa dental prosthesis, the milling job can be easily routed to a secondmill or mill group, and the machining instructions for that dentalprosthesis can be modified according to an enlargement factor of anothermaterial blank available for use by that mill or mill group with minimalhuman intervention.

Example 3—Dental Prosthesis Database

FIG. 9 illustrates exemplary dental prosthesis information 400 for adental prosthesis to be milled by the dental milling system 100. Thedental prosthesis information 400 can be provided to the dentalprosthesis management system 102 as dental prosthesis information 152and stored as an entry in the dental prosthesis database 150.

The dental prosthesis information 400 can include such information asthe type of dental prosthesis 410 to be manufactured (e.g., crown,implant, bridge, etc.), a material type 420 from which the dentalprosthesis is to be manufactured, an identification 430 of the tooth orportion of a tooth to be prosthetically recreated, and situational data440 concerning the position of the dental prosthesis in a patient'smouth (e.g., data concerning a dental impression, or photographic data).In addition, the dental prosthesis information 400 can include thedesign information created for the design of the dental prosthesis 410to be manufactured, such as design information created using a dentalCAD software program. In some embodiments, the dental prosthesisinformation 400 can also include identification information 450concerning a dentist or dental office requesting manufacture of thedental prosthesis, and/or patient identification information.

Example 4—Material Blank Database

FIG. 10 illustrates exemplary material blank information 500 for amaterial blank, such as the material blanks 200, 300 described above.The material blank information 500 can be stored on one or more barcodesassociated with each material blank, such as barcodes 204, 304 of thematerial blanks 200, 300, and can be provided to the dental prosthesismanagement system 102 as material blank information 170 and stored as anentry in the material blank information database 166.

The material blank information 500 can include such information asidentification data 510 (for example, a serial number), the type ofmaterial 520 from which the material blank is made, a color shadeidentifier 530 identifying a color shade of the material blank, and amaterial blank enlargement factor 540 of the material blank. Inaddition, the material blank information 500 can also includeinformation such as the size, shape, or other physical characteristicsof the material blank.

Example 5—Exemplary Method of Machining a Dental Prosthesis

FIG. 11 is a schematic block diagram illustrating a representativemethod of milling a dental prosthesis. At process block 602, the dentalmilling system 100 can receive dental prosthesis information for a newdental prosthesis to be milled, which can be stored in a database, suchas the dental prosthesis database 150 of FIG. 7. Based at least in parton the dental prosthesis information, a material from which to machinethe dental prosthesis can be selected at process block 604. At processblock 606, machining instructions for machining the dental prosthesiscan be determined based at least in part on the dental prosthesisinformation and a nominal enlargement factor corresponding to theselected material. At process block 608, the machining instructions canbe stored in, for example, the machining instructions database 134 ofFIG. 7.

At process block 610, the dental milling system 100 can receive arequest from a mill or a mill group control module for a dentalprosthesis to be milled by the mill or mill group. At process block 612,the dental prosthesis can be associated with the mill or mill group. Atprocess block 614, the machining instructions associated with the dentalprosthesis can be transmitted to the mill or mill group control module.In some embodiments, the machining instructions can include informationof the nominal enlargement factor used to determine the machininginstructions. At process block 616, a material blank can be selectedfrom which to mill the dental prosthesis, and a material blank actualenlargement factor of the selected material blank can be obtained fromthe material blank at process block 618. Using the material blank actualenlargement factor, a correction factor can be determined at block 620.The machining instructions can then be modified according to thecorrection factor (i.e., according to a difference between the nominalenlargement factor and the material blank actual enlargement factor) atblock 622 to determine modified machining instructions, and the materialblank can be placed in the appropriate mill at block 624. The dentalprosthesis can then be milled according to the modified machininginstructions at block 626. At block 628, the milled dental prosthesiscan be removed from the mill and made available for further processing.

Example 6—Exemplary Computing Environment

FIG. 12 depicts a generalized example of a suitable computingenvironment 700 in which the described innovations may be implemented.The computing environment 700 is not intended to suggest any limitationas to scope of use or functionality, as the innovations may beimplemented in diverse general-purpose or special-purpose computingsystems. For example, the computing environment 700 can be any of avariety of computing devices (e.g., desktop computer, laptop computer,server computer, tablet computer, gaming system, mobile device,programmable automation controller, etc.) that can be incorporated intoa computing system comprising one or more computing devices.

With reference to FIG. 12, the computing environment 700 includes one ormore processing units 710, 715 and memory 720, 725. In FIG. 12, thisbasic configuration 730 is included within a dashed line. The processingunits 710, 715 execute computer-executable instructions. A processingunit can be a central processing unit (CPU), a processor in anapplication-specific integrated circuit (ASIC), or any other type ofprocessor. In a multi-processing system, multiple processing unitsexecute computer-executable instructions to increase processing power.For example, FIG. 12 shows a central processing unit 710 as well as agraphics processing unit or co-processing unit 715. The tangible memory720, 725 may be volatile memory (e.g., registers, cache, RAM),non-volatile memory (e.g., ROM, EEPROM, flash memory, etc.), or somecombination of the two, accessible by the processing unit(s). The memory720, 725 stores software 780 implementing one or more innovationsdescribed herein, in the form of computer-executable instructionssuitable for execution by the processing unit(s).

A computing system may have additional features. For example, in someembodiments, the computing environment 700 includes storage 740, one ormore input devices 750, one or more output devices 760, and one or morecommunication connections 770. An interconnection mechanism (not shown)such as a bus, controller, or network, interconnects the components ofthe computing environment 700. Typically, operating system software (notshown) provides an operating environment for other software executing inthe computing environment 700, and coordinates activities of thecomponents of the computing environment 700.

The tangible storage 740 may be removable or non-removable, and includesmagnetic or optical media such as magnetic disks, magnetic tapes orcassettes, CD-ROMs, DVDs, or any other medium that can be used to storeinformation in a non-transitory way and can be accessed within thecomputing environment 700. The storage 740 stores instructions for thesoftware 780 implementing one or more innovations described herein.

The input device(s) 750 may be, for example: a touch input device, suchas a keyboard, mouse, pen, or trackball; a voice input device; ascanning device; any of various sensors; another device that providesinput to the computing environment 700; or combinations thereof. Forvideo encoding, the input device(s) 750 may be a camera, video card, TVtuner card, or similar device that accepts video input in analog ordigital form, or a CD-ROM or CD-RW that reads video samples into thecomputing environment 700. The output device(s) 760 may be a display,printer, speaker, CD-writer, or another device that provides output fromthe computing environment 700.

The communication connection(s) 770 enable communication over acommunication medium to another computing entity. The communicationmedium conveys information, such as computer-executable instructions,audio or video input or output, or other data in a modulated datasignal. A modulated data signal is a signal that has one or more of itscharacteristics set or changed in such a manner as to encode informationin the signal. By way of example, and not limitation, communicationmedia can use an electrical, optical, RF, or other carrier.

Any of the disclosed methods can be implemented as computer-executableinstructions stored on one or more computer-readable storage media(e.g., one or more optical media discs, volatile memory components (suchas DRAM or SRAM), or nonvolatile memory components (such as flash memoryor hard drives)) and executed on a computer (e.g., any commerciallyavailable computer, including smart phones, other mobile devices thatinclude computing hardware, or programmable automation controllers)(e.g., the computer-executable instructions cause one or more processorsof a computer system to perform the method). The term computer-readablestorage media does not include communication connections, such assignals and carrier waves. Any of the computer-executable instructionsfor implementing the disclosed techniques as well as any data createdand used during implementation of the disclosed embodiments can bestored on one or more computer-readable storage media. Thecomputer-executable instructions can be part of, for example, adedicated software application or a software application that isaccessed or downloaded via a web browser or other software application(such as a remote computing application). Such software can be executed,for example, on a single local computer (e.g., any suitable commerciallyavailable computer) or in a network environment (e.g., via the Internet,a wide-area network, a local-area network, a client-server network (suchas a cloud computing network), or other such network) using one or morenetwork computers.

For clarity, only certain selected aspects of the software-basedimplementations are described. Other details that are well known in theart are omitted. For example, it should be understood that the disclosedtechnology is not limited to any specific computer language or program.For instance, the disclosed technology can be implemented by softwarewritten in C++, Java, Perl, JavaScript, Adobe Flash, or any othersuitable programming language. Likewise, the disclosed technology is notlimited to any particular computer or type of hardware. Certain detailsof suitable computers and hardware are well known and need not be setforth in detail in this disclosure.

It should also be well understood that any functionality describedherein can be performed, at least in part, by one or more hardware logiccomponents, instead of software. For example, and without limitation,illustrative types of hardware logic components that can be used includeField-programmable Gate Arrays (FPGAs), Program-specific IntegratedCircuits (ASICs), Program-specific Standard Products (ASSPs),System-on-a-chip systems (SOCs), Complex Programmable Logic Devices(CPLDs), etc.

Furthermore, any of the software-based embodiments (comprising, forexample, computer-executable instructions for causing a computer toperform any of the disclosed methods) can be uploaded, downloaded, orremotely accessed through a suitable communication means. Such suitablecommunication means include, for example, the Internet, the World WideWeb, an intranet, software applications, cable (including fiber opticcable), magnetic communications, electromagnetic communications(including RF, microwave, and infrared communications), electroniccommunications, or other such communication means.

In view of the many possible embodiments to which the principles of thedisclosure may be applied, it should be recognized that the illustratedembodiments are only preferred examples and should not be taken aslimiting the scope of the disclosure. Rather, the scope of the inventionis defined by all that comes within the scope and spirit of thefollowing claims.

What is claimed is:
 1. A method for fabricating a dental prosthesis froma material blank, comprising: over a network, receiving data concerninga design for a dental prosthesis using a dental prosthesis database;selecting a material from which to machine the dental prosthesis; usinga machining instructions tool to determine machining instructions formachining the dental prosthesis based on the data concerning a designfor the dental prosthesis and a nominal enlargement factor correspondingto the selected material; using a dental prosthesis selection module toassociate the machining instructions with a dental prosthesis millingmachine; using a controller to select a material blank comprised of theselected material, determine a material blank enlargement factor of theselected material blank, and modify the machining instructions accordingto a difference between the nominal enlargement factor and the materialblank enlargement factor; and machining the dental prosthesis with themilling machine according to the modified machining instructions.
 2. Themethod of claim 1, wherein modifying the machining instructions furthercomprises: transmitting the machining instructions to the controller,which is associated with the milling machine; and modifying themachining instructions with the controller.
 3. The method of claim 1,wherein modifying the machining instructions further comprises:modifying the machining instructions; and transmitting the modifiedmachining instructions to the milling machine.
 4. The method of claim 1,wherein determining the material blank enlargement factor furthercomprises scanning a barcode associated with the material blank, thebarcode including data indicative of the material blank enlargementfactor.
 5. The method of claim 1, wherein modifying the machininginstructions further comprises modifying a milling tool path accordingto the difference between the nominal enlargement factor and thematerial blank enlargement factor.
 6. The method of claim 1, whereindetermining the material blank enlargement factor further comprisesretrieving information concerning the material blank from a materialblank database.
 7. The method of claim 1, wherein: the data concerningthe dental prosthesis includes color shade data; and selecting thematerial blank further comprises selecting a material blank based atleast in part on the color shade data.
 8. One or more non-transitorycomputer-readable media storing computer executable instructions forcausing a computer to perform a method for fabricating a dentalprosthesis from a material blank, the method comprising: over a network,receiving data concerning a design for a dental prosthesis using adental prosthesis database; selecting a material from which to machinethe dental prosthesis; using a machining instructions tool to determinemachining instructions for machining the dental prosthesis based on thedata concerning a design for the dental prosthesis and a nominalenlargement factor corresponding to the selected material; using adental prosthesis selection module to associate the machininginstructions with a dental prosthesis milling machine; using acontroller to select a material blank comprised of the selectedmaterial, determine a material blank enlargement factor of the selectedmaterial blank, and modify the machining instructions according to adifference between the nominal enlargement factor and the material blankenlargement factor; and machining the dental prosthesis with the millingmachine according to the modified machining instructions.
 9. The one ormore non-transitory computer-readable media of claim 8, whereinmodifying the machining instructions further comprises: transmitting themachining instructions to a controller associated with the millingmachine; and modifying the machining instructions with the controller.10. The one or more non-transitory computer-readable media of claim 8,wherein modifying the machining instructions further comprises:modifying the machining instructions; and transmitting the modifiedmachining instructions to the milling machine.
 11. The one or morenon-transitory computer-readable media of claim 8, wherein determiningthe material blank enlargement factor further comprises scanning abarcode associated with the material blank, the barcode including dataindicative of the material blank enlargement factor.
 12. The one or morenon-transitory computer-readable media of claim 8, wherein modifying themachining instructions further comprises modifying a milling tool pathaccording to the difference between the nominal enlargement factor andthe material blank enlargement factor.
 13. The one or morenon-transitory computer-readable media of claim 8, wherein determiningthe material blank enlargement factor further comprises retrievinginformation concerning the material blank from a material blankdatabase.
 14. The one or more non-transitory computer-readable media ofclaim 8, wherein: the data concerning the dental prosthesis includescolor shade data; and selecting the material blank further comprisesselecting a material blank based at least in part on the color shadedata.